Preston recorded their first home league win since September against managerless Bristol City in a heated match that ended with two red cards.
Preston's Kevin Davies nodded across goal for Jack King to head home his first goal of the season.
The visitors came closest to equalising from a wide Simon Gillett shot and a close-range Aden Flint header.
Both sides finished with 10 men when Karleigh Osborne and Paul Gallagher were dismissed for scuffling late on.
The result kept North End third in League One, but piled more misery on Bristol City, who slipped 23rd after
sacking head coach Sean O'Driscoll on Thursday.
VIEWS FROM THE DRESSING ROOM
Bristol City caretaker manager John Pemberton told BBC Radio Bristol:
"We definitely deserved more from the game today.
"In the first 20 minutes I thought we were on the back foot but other than that I thought we were excellent.
"In the second half we made a good team look ordinary again. We've created chances but we haven't taken them.
"I cannot fault the desire of what they've done, and the spirit they have shown, and we will now move onto the next game."
Preston North End 23 Rudd 05 Clarke 03 Laird Booked 02 Keane 22 King 06 Wright Booked 07 Humphrey (Huntington - 95' ) 30 Brownhill (Byrom - 79' ) 09 Davies 10 Beavon (Hume - 83' ) 12 Gallagher Dismissed Substitutes 01 Stuckmann 04 Huntington 13 Byrom 16 Buchanan 17 Monakana 24 Hayhurst 27 Hume Bristol City 13 Parish 21 Pack 17 Cunningham (Bryan - 81' ) 03 Williams 05 Flint 35 Osborne Dismissed 02 Moloney (Taylor - 84' ) 11 Wagstaff 10 Emmanuel-Thomas 09 Baldock 34 Gillett Substitutes 01 Fielding 15 Bryan 16 Wynter 18 Taylor 22 Shorey 23 Harewood 28 McLaughlin
Ref: Richard Clark